Flash assist system, digital image capture device using same and flash assist method thereof

ABSTRACT

A flashing assist system is used in a digital image capture device that includes a camera module, a flash unit and a display. The camera module is capable of determining an object distance from the image capture device to an object. The flash unit is capable of providing varying flash intensity by determining a flash distance. The display is capable of displaying digital images and interactive information. The flash assist system includes a read unit, a determination unit and a generating unit. The read unit is configured for reading the object distance and the flash distance. The determination unit is configured for determining a target area of the flash unit using the object distance and the flash distance. The generating unit is configured for generating a preview of the object and the target area on the display.

BACKGROUND

1. Technical Field

The present disclosure relates to camera flash systems and,particularly, to a flash assist system, a digital image capture deviceusing the flash assist system, and a flash assist method thereof.

2. Description of Related Art

A digital image capture device typically includes a flash unit capableof providing momentary illumination at the moment of capture tocompensate for insufficient environmental illumination, and beingoperated manually to provide specific compensation for different ambientlight conditions. However, it is difficult to set accurate flashintensity because of varying environmental requirements.

Therefore, it is desirable to provide a flash assist system, a digitalimage capture device using the flash assist system, and a flash assistmethod thereof which can overcome the limitations described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a digital image capture device, accordingto an exemplary embodiment.

FIG. 2 is a schematic view of the back of the digital image capturedevice of FIG. 1, according to an exemplary embodiment.

FIG. 3 is another schematic view of the back of the digital imagecapture device of FIG. 1, according to an exemplary embodiment.

FIG. 4 is a flowchart of a flash assist method, according to anexemplary embodiment.

DETAILED DESCRIPTION

Embodiments of the disclosure are now described in detail with referenceto the drawings.

Referring to FIG. 1, a digital image capture device 100 includes acamera module 10, a flash unit 20, a display 30, an input unit 40, astorage unit 50, an image processing unit 60, and a flash assist system70. The digital image capture device 100 can be, but is not limited to,a digital still camera or a mobile phone equipped with a camera moduleand a flash unit.

The camera module 10 is configured for capturing an image by generatingcorresponding image signals. The camera module 10 automatically focuseson an object, and is capable of determining an object distance from theimage capture device thereto. In detail, the camera module 10 is drivenby a focus motor (not shown) step by step until a clear image isproduced. Accordingly, the object distance can be calculated accordingto the number of steps that the focus motor takes to achieve the clearimage using corresponding software modules executed in the digital imagecapture device 100. Alternatively, the camera module 10 can include adistance-measurement unit (not shown), which emits a light beam to thefocused object, calculates the time before it receives the reflectedlight, and determine the object distance accordingly.

The flash unit 20 is configured for flash at the moment of image captureto compensate for insufficient environmental illumination. The flashunit 20 is capable of providing varying flash intensity by setting aflash distance via the input unit 40. The flash distance is a distancefrom the flash unit 20 to a position at which the flash is attenuated toprovide a pre-determined intensity.

The display 30, such as a liquid crystal display, is configured fordisplaying captured digital image(s) and interactive information. Theinput unit 40, such as a keypad, is configured for receiving user input.The display 30 and the input unit 40 constitute a user interface of theimage capture device 100. Alternatively, the display 30 and the inputunit 40 can be integrated into a touch-screen.

The storage unit 50 is configured for storing captured digital images.

The image processing unit 60 is configured for processing the capturedimage signals output by the camera module 10, and then outputting acorresponding digital image to the display 30 and/or the storage unit50.

The flash assist system 70 includes a read unit 72, a determination unit74, and a generating unit 76. The read unit 72 is configured for readingthe object distance and the flash distance from the camera module 10 andthe input unit 40 correspondingly. The determination unit 74 isconfigured for determining a target area using the flash distance andthe object distance, based upon parameters of the flash unit 20, such asan emission angle of flash from the flash unit 20. The generating unit76 is configured for generating a preview of the object and the targetarea on the display 30. In the present embodiment, the generating unit76 illustrates the target area via forming a help line 78 at the edge ofthe target area. If the flash distance exceeds the object distance, thehelp line 78 surrounds the object in the preview as shown in FIG. 2,such that the target area covers the whole object. If the flash distanceis less than the object distance, the help line 78 may cross the objectas shown in FIG. 3 such that the target area covers only a part of theobject, indicating the need to increase the flash distance forsufficient illumination.

In this way, the digital image capture device 100 illustrates the targetarea that can be illuminated by the flash unit 20, thereby providing thenecessary information for accurate manual setting of the flashintensity.

FIG. 4 shows a flash assist method as disclosed, which can beimplemented by a digital image capture device such as that alsodisclosed here, as follows.

In Step 202, an object distance from the digital image capture device100 to an object and a flash distance are acquired. Camera module 10automatically focuses on an object, and calculates the distance from theimage capture device to the object. The flash distance is input from theinput unit 40. The read unit 72 of the flash assist system 70 reads theobject distance and the flash distance.

In Step 204, a target area is determined using the object distance andthe flash distance. The determination unit 74 determines a target areato be illuminated on the display 30 using the object distance and theflash distance. If the flash distance exceeds the object distance, thetarget area covers the whole object as shown in FIG. 2. If the flashdistance is less than the object distance, the target area may coveronly a part of the object as shown in FIG. 3, indicating the need toincrease the flash distance for sufficient illumination.

In Step 206, a preview of the object and target areas is generated. Thegenerating unit 76 generates a preview of the object and the target areaon the display 30. The target area can be illustrated by a help linegenerated at the edge thereof.

It will be understood that the above particular embodiments and methodsare shown and described by way of illustration only. The principles andthe features of the present invention may be employed in various andnumerous embodiments thereof without departing from the scope of theinvention as claimed. The above-described embodiments illustrate thescope of the invention but do not restrict the scope of the invention.

1. A flash assist system for use in a digital image capture device, thedigital image capture device comprising a camera module capable ofdetermining a distance from the digital image capture device to anobject, a flash unit capable of providing varying flash intensity bydetermining a flash distance, and a display capable of displayingdigital images and interactive information, the flash assist systemcomprising: a read unit configured for reading the object distance andthe flash distance; a determination unit configured for determining atarget area of the flash unit using the object distance and the flashdistance; and a generating unit configured for generating a preview ofthe object and the target area on the display.
 2. The flash assistsystem as claimed in claim 1, wherein the target area covers the wholeobject if the flash distance exceeds the object distance.
 3. The flashassist system as claimed in claim 1, wherein the target area isillustrated by showing a help line at the edge thereof.
 4. A digitalimage capture device comprising: a camera module capable of determiningan object distance from the image capture device to an object; a flashunit capable of providing varying flash intensity by determining a flashdistance; a display capable of displaying digital images and interactiveinformation; and a flash assist system capable of reading the objectdistance and the flash distance, determining a target area of the flashunit using the object distance and the flash distance, and generating apreview of the object and the target area on the display.
 5. The digitalimage capture device as claimed in claim 4, wherein the camera moduleautomatically focuses on the object, and is driven by a focus motor stepby step until a clear image is generated, and the object distance iscalculated according to the number of steps that the focus motor takesto acquire the clear image.
 6. The digital image capture device asclaimed in claim 4, wherein the camera module comprises adistance-measurement unit capable of emitting a light beam to theobject, calculating the time before it receives the light reflected fromthe object, and calculating the object distance accordingly.
 7. Thedigital image capture device as claimed in claim 4, wherein the targetarea covers the whole object if the flash distance exceeds the objectdistance.
 8. The digital image capture device as claimed in claim 4,wherein the target area is illustrated by showing a help line at theedge thereof.
 9. A flash assist method for a digital image capturedevice, comprising: acquiring an object distance from the digital imagecapture device to an object and a flash distance; determining a targetarea using the object distance and the flash distance; and generating apreview of the object and the target area.
 10. The flash assist methodas claimed in claim 9, wherein the target area covers the whole objectif the flash distance exceeds the object distance in the determiningstep.
 11. The flash assist method as claimed in claim 9, wherein thetarget area is illustrated by showing a help line at the edge thereof inthe generating step.